The additionalMediaInfo will contain additional media info provided by
the publisher. Video content is made available only to Twitter official
clients when embeddable=false. In this case, all video URLs provided in
the payload will be Twitter-based, so the user can open the video in a
Twitter owned property by clicking the link.
An array of integers indicating the offsets within the Tweet text where
the URL begins and ends. The first integer represents the location of the
first character of the URL in the Tweet text. The second integer
represents the location of the first non-URL character occurring after the
URL (or the end of the string if the URL is the last part of the Tweet
text).